70 GR1ESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



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Lithological character of divisions. 



4. Hard grey concretionary lime- 

 stone in thick beds. 



3. Earthy limestone 



10 



2. Limestone alternating with 

 shales. 



1 . Dark shales with limestone par- 

 tings. 



Zones of 



Phychites gerardi Bfd 



Rhynchonella semi- 

 plecta Mun. Var. 



In Germany. 



Muschelkalk. 



Posidonomya sp. 



Otoceras w d- 

 wardi. 



Buntsandstein. 



The most marked feature in all the triassic sections which I have 



examined is the structural and lithological con- 

 Lower trias. tinuity which exists between the Productus 

 shales and the lowest trias beds. Whilst the former are not only 

 sharply separated from the underlying carboniferous in lithological 

 character but overlap the same also, they form a continuous series of 

 beds with the overlying trias. In spite of lithological differences 

 between the various beds which compose the permo-trias-rhaetic 

 group, there is a certain character common to all the divisions. 

 Shales, limestones and dolomites all weather a deep sienna tint, 

 whilst the beds successively pass one into the other, or show their 

 close relationship by frequent alternations. There is scarcely any 

 variation in the character and composition of the lower trias in any 

 of the sections which I surveyed. Practically from the most eastern 

 sections, those of Byans to Spiti, west of the Sutlej, the succession 

 of beds remains the same. In all of them the lower trias beds with 

 the underlying Productus shales are present. 



Stoliczka during his brief examination of Spiti fell into the error 



of assuming that the upper part of the lower trias, the limestone with 



Ptychites gerardi, rests immediately on the carboniferous Kuling 



shales, and that therefore the lowest trias, corresponding to the 



( 70 ) 



